Solar panel configuration and pv wire gauge?

[Travis55]

I'm running two LV6548 inverters in split phase, the max inputs are as follows for one inverter: Max PV 500V, (2 x 250v inputs).

I have 12 panels (4 per each solar array ground mount). Here are the specs on the panels.

• Power Rating: 395W
• Number of Cells: 108
• Imp 12.81A
• Vmp 30.84V
• Isc 13.70A
• Voc 36.98V
• Power Tolerance: 0~+5W

I have about a 100ft run from panel to inverter. I originally thought about doing 3 runs, one per rack (4 panels), but I think the amps get too high and voltage too low (38A, 123V)?

If I ran two strings of 6 and 6 I believe I end up with 12.81A and 185.04V per string.

Is the the optimal way to do this, and would I connect one string to each inverter, or both strings to one inverter? Would 10 awg pv wire be sufficient?

Thanks!!

 

[DougfromdaUP]

Is the voltage limit 250 volts per mppt or 500?

 

[Travis55]

Is the voltage limit 250 volts per mppt or 500?

That's a great question, I looked in the manual and don't quite understand if it's 500V max on each of the two MPPT (1000V total), or 500V max total on each inverter (250V x 2)?

 

[Travis55]

That's a great question, I looked in the manual and don't quite understand if it's 500V max on each of the two MPPT (1000V total), or 500V max total on each inverter (250V x 2)?

View attachment 218636

Upon second look it appears the Max. Input Current answers that, 18A x 2. It wouldn't really be possible to get 500V and stay under 18A. So I assume its 250V max on each of the MPPT inputs.

 

[DougfromdaUP]

No, it’s plainly 500 volts. You don’t need to add them together; the limit is the same for each mppt.

 

[DougfromdaUP]

The “2 x18” means that there are 2 mppt, each accepting 18 amps. So your plan to use two strings is fine.

It looks like one inverter can handle 8000 watts, so it would be ok to use the mppt s of one inverter for both strings. If it’s not too hard to wire, though, I’d put one string on each inverter.